This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The hypothesis of the study: Attenuated hydrolysis of stored cholesterol esters in atherosclerotic-lesion associated foam cells contributes to decreased cholesterol efflux capacity of serum HDL particles in patients with atherosclerosis or risk for atherosclerosis and is associated with decreased vascular endothelial function. The present research proposal aims to assess cholesterol efflux potential of serum, and its relationship to ApoAI / ApoAII ratio of HDL particles, monocyte/macrophage CEH expression and vascular endothelial function. This will be a cross-sectional pilot study investigating cholesterol efflux potential, ApoAI / ApoAII ratio, cholesterol ester hydrolysis expression, and endothelial function in three groups.